Electrical relay and the like



July 5, 1932. E. F. WESTON ELECTRICAL RELAY AND THE LIKE Filed July 17.1930 4 Sheets-Sheet 1 July 5, 1932. E. F. WESTON ELECTRICAL RELAY ANDTHE LIKE Filed July 17 1950 4 Sheets-Sheet 2 July 5, 1932. E. F. WESTONELECTRICAL RELAY AND THE LIKE 6 Filed July 17, 1930 4 sheets-she t a Jly 5,1932. E; F. WESTON 1,866,436

ELECTRICAL RELAY AND THE LIKE Filed July 17, 1930 4 she'ets-sheet 4Patented July 5, 1932 I UNITED STATES PATENT OFFICE EDWARD F. WESTON, OFNEWARK, NEW JERSEY, ASSIGNOR TO WESTON ELECTRICAL INSTRUMENTCORPORATION, OF NEWARK, NEW JERSEY, A CORPORATION OF JERSEY ELECTRICALRELAY AND THE LIKE Application ma July 17, 1930. semi K051683584.

This invention relates to electrical instruments of the known type whichincludes a c011 movable in the field of a permanent magnet.

The invention is particularly useful in connection with instruments,such as relaysor measuring instruments, of relatively large size butcertain features may be advantageously employed with instruments bf anysize.

1 An object of the invention is to provide an instrument which may bereadily assembled and from which the principal parts of the assembly maybe removed, for inspection or repair, without disturbing other parts ofthe instrument. A further ob ect 15 to provide an instrument having amoving coil system of substantial axial length and in which the bearingsfor mounting the coil are substantially unaffected by temperaturechanges. go Further objects are to improve and SlIIlPllfy variousstructural details of a moving 0011 relay, such as, for example, therelay contacts and the mountings therefor.

These and other objects of the invention will be apparent from thefollowing specification, when taken with the accompanying drawings inwhich:

Fig. 1 is a central longitudinal section through a relay embodying theinvention,

Fig. 2 is a transverse section taken on line 22 of Fig. 1,

Fig. 3 is an interior plan view of the relay base,

Fig. 4 is an end elevation, with parts shown in section, of the relaybase,

Fig. 5 is a perspective view of the insulating plate upon which therelay contacts are mounted,

Fig. 6 is a fragmentary side view, partly in section, of a relay contactand ad acent portions of the mounting plate, and

Fig. 7 is a transverse section on line 7-7 of Fig. 6.

As shown in Fig. 1, all parts of the relay assembly are mounted directlyu on or supported from a base 1 ofmolde insulating material which maybe, and preferably is of the phenolic resin type. The base may be of anyappropriate shape, usually rectangular as shown in Fig. 3, and ispreferably provided with a shallow groove 2 at its upper surface toreceive a cover 3 which, with the base 1, forms a housing for the relay.To permit inspection of the moving system and contacts, the cover 3 maybe provided with an opening which is closed with a glass plate 4. Theportions of the base 1 which 1e outside of the groove 2 may be recessedand apertured, as indicated at 5 in Fig. 3,

to receive binding posts 6 and other apertures 7 are provided forreceiving screws or bolts 8 by which the relay may be secured toa panelor other appropriate support.

The outer edge of the base 1 is provided v with a depending flange 9which rovides a I clearance space beneath the lower ace of the base 1. Apanel 10 is secured to the base to cover or protect the electricalconnections and bolt heads, terminals or the like which extend throughor into this clearance space. With the exception of the supporting ofall parts of the relay from the base 1, as will be explained in furtherdetail hereinafter, the various structural features noted above may bevaried at will to satisfy the general design requirement for anyparticular instrument or relay.

In accordance with the present invention, an integral abutment orprojection 11 extends above the base 1 within and closely adjacent oneedge of the space defined by the groove 2 and cover 3. One flat face ofa cylindrical core 12 which has the form, in cross-section, of a zone ofa circle, rests against the inner face of the abutment 11,

and the insulating plate 13 rests a ainst the 1 flat face of the core,the core and p ate being secured to the abutment 11 by bolts 14 whichpass transversely through these elements.

As best shown in Fig. 4, the abutment 11 is provided with two passages15 whose axes preferably are parallel to each other and to the axis ofthe core 12. The passages 15 are continued through the base 1 bypassages 16 of smaller diameter. The pillars 17 that carry the bridgemember 18 are arranged in and have radial faces which bear against thelower ends of passages 15, the reduced ends 19 of the pillars extendingthrough the passages 16 to receive nuts for securing the pil lars to thebase. The pillars 17 do not contact with the wall of the passages butthe reduced ends 19 preferably-fit tightly within the passages 16 of thebase.

The bridge member 18 provides a support for the upperjewel bearing 20and a similar bearing 21 is mounted directly in the base 1. The movingcoil system-is mounted in bearings 20, 21 and includes the contact arm23, appropriate means for anchoring the inner ends of an spring 24 andanchors 25 for a pair of opposite-ly wound lower torsion springs 26. Theouter ends of the respective springs 26 are secured to metal straps 27that are accurately positioned on the base 1 by the pairs of lugs 28.The springs 26 are insulated from each other and from the coil pivot bythe bushing 29 and may therefore be employed as the ads to the winding22.

The insulating plate 13 is provided, adjacent its upper inner edges,with integral hooked arms 30, see Figs. 5 and 6, for receiving the relaycontacts.

portion of each hooked arm 30, the opposed surfaces of each pair ofabutments comprising portions of the surface of a right cylinder and theinner surfaces of all of the abut ments lying substantially in a singleplane.

The circular heads of the pairs of bushings 33 rest against thecylindrical surfaces of abutments 31, 32 and the spring washer 34 whichforms a part of each contact assembly has radial projections 35 whichbear against the plane surfaces of a pair of "abutments to preventrotation of the washer. The contact point 36 is mounted uponthe end of ascrew 37 that is threaded through the bushings 33. In assembling theparts, the bushings 33 and washer 34 areplaced on a hooked arm, thebushings having flat sides which engage the opposite faces of the slotsin the arm to prevent rotation of the bushings. The bushings are pressedtowards each other to compress the spring washer and the contact screw37 is threaded the desired distance into the bushings. b

Upon releasing the the spring washer any backlash in the inadvertentrotation of the screw 37.

The magnetic field in which the winding 22 is located maybe provided bya permanent magnet in the form of a U-shape bar 38 having attached polepieces 39. To facilipressure on the bushings, 35 expands to eliminatetate the location of the permanent magnet 1n a definite predeterminedrelation to the moving system of the relay, the upper face of base 1 ispreferably countersunk to leave lugs 40 that provide a three-pointsupport for the bar 38 and the corners of the abutment 11 and insulatingplate 13 are notched, as indicated at 41 and 42 respectively, to formguide channels for the edges of the the winding 22,

upper torsion Abutments 31,- 32 extend laterally from the upper andlower spective contact points 36.

assembly and to preventpole pieces 39. The permanent magnet as-" semblyis secured to the base by bolts 43.

' Instruments of this type usually include a resistance for determiningthe voltage'to be impressed across the winding 22, and when one isrequired the resistance winding or spool 44 may be supported in thespace within the bar magnet 38 by a plate 45 that is secured to thelower face of the base 1.

To facilitate the assembly of the instrument, an opening 46 is providedin the central portion of the base.

tIn assemblying the instrument, the pillars 15 are fixed in-place andthe bridge member 18 is mounted on the pillars. The movin system is thenplaced in position on the jewel bearings. Thorough inspection'and/oradjustment of the moving system are possible since none ofthe otherparts are in place and the opening. 46 in the base 1 is not obstructed;The core 12 and insulating plate 1-3, with'the contacts assembledthereon, are then secured to the abutment 11 and the resistance spool 44is mounted on the base. The appropriate electrical connections are thenmade. Asstated above, the connections to the winding 22 of the movingsystem are made through the lower springs 26, and, similarly, theconnection to the contact arm 23 may be made through the upper spring24. The radial projections35 on spring washers 34 serve as electricalterminals for the re- When the wiring is completed, the permanent magnetis slipped into place, being guided by the recessed edges of abutment 11and plate 13, and secured by bolts 43. After the final inspection andadjustment, the cover 3 and sub-panel 10 are secured to the base tocomplete the assembly.

The pillars 17 are formed of a metal or alloy which has substantiallythe same coefficient of expansion, for temperature changes, as themoving coil system. Since the pillars 17 are spaced from the abutment11, the spacing of the bridge member and upper jewel hearing from thelower jewel caring is not affected by the expansion of the abutment 11which,if formed ofaphenolic resin, has a relatively high coefficient ofexpansion. This feature is of primary importance when instruments havingrelatively long coil systems are subjected to a wide range oftemperature. per bearing upon pillars which have the same coeflicient ofexpansion as the moving system, the adjustment of the bearings remainssubstantially independent of temperature changes.

It will be apparent that the invention is not limited to electricalinstruments of the relay type but may be embodied in measuringinstruments in which the pivoted coil moves a pointer over a scale.

By mounting the up- 1 I Iclaim:

1. In an electrical instrument of the crmanent magnet and movable coiltype, a ase of insulatingmaterial, an abutment rising above said base, acore secured to said abutment, a lower jewel bearing mounted in said tosaid base and passing through but not contacting with said abutment, abridge member mounted on said pillars, an upper jewel bearing carried bysaid bridge ,member, and a coil system pivotally supported by saidbearings.

2. The invention as set forth in claim 1, wherein the temperaturecoeflicients of expansion of said pillars and said coil system k aresubstantially equal.

3. The invention as set forth in claim 1, wherein the said insulatingbase is provided with an aperture adjacent the said lower jewel bearing,said aperture being of a size to permit access to the moving systemthrough the insulating base.

4. In a relay of the permanent magnet and pivoted coil type, a base ofinsulating material having an integral abutment extending above thesame, a core, an insulating plate carrying contacts, means securing saidcore' and contact plate to said abutment, a moving system including acontact arm and a coil mounted for angular movement about the axis ofsaid core, and a permanent magnet secured to said base and having polescooperating with said core to establish a magnetic. field in which saidcoil is positioned.

5. The invention as set forth in claim 4,

wherein the opposed faces of said abutment and contact plate providechannels for guiding said magnet, as it moved from said base,

is assembled on or reto prevent the same from contacting with saidmoving system.

6. The invention as set forth in claim 4, wherein the lower bearing forsaid moving system is mounted in per bearing is supported by metalpillars having substantially the coeflicient of expansion as said movingsystem, whereby temperature change willnot affect the adjustment of saidmoving system in said bearings.

7. In an electrical magnet and pivoted coil type, a base, a contactplate ofinsulating material supported from said base, said plate havinghooked arms, metal bushings extending into the apsaid bushings and armsertures provided by eachof said hooked arms, having cooperating ortionspreventing rotation of said bushlngs, a spring washer between each ofsaid arms and a bushing mounted therein, and contact screws threadedthrough the pair of I bushings mounted on the respective arms.

8. The invention as set wherein each of said washers is provided with aradial extension which serves as anelectrical terminal for the contactscrew.

said base, and the up-,

same temperature forth in claim 5,

ing an upper pivotal support for said moving system; the space definedby the opposed faces of said poles being larger, as viewed axially ofthe moving system, than the space occupied by said moving system andupper support therefor, whereby the magnet may be removed from said basewithout disturbing said moving system.

.10. The invention as set forth in claim 9, wherein said abutment andsaid insulating contact plate havecsurfaces cooperating with said ma netpoles to guide the magnet as it is assem led on or removed from saidbase.

11. A contact assembly for use in an electrical relay of the typeincluding a magnet, a core between the poles of said magnet, and a coilpivotally supported for angular movement in the air gaps between saidcore and the poles of said magnet; said contact assembly comprising aplate of insulating material adapted to be supported against one face ofsaid core, a pair of metal bushings mounted .on said insulating plate,a'contact screw threaded through said bushings, and cooperating means onsaid plate andbushings to prevent rotation of the latter. 7

12. The invention as set forth in claim 11, in combination with a springwasher tending to effect relative movement of said bushings axially ofsaid contact screw, whereby backlash is eliminated.

In testimony whereof, I aflix my signature.

EDWARD F. WESTON.

relay of the permanent

